1. Field of Invention
The invention relates to a chip package and more particularly to a chip package with a through substrate via (TSV) structure and a fabrication method thereof.
2. Description of Related Art
As demand for electronic or optoelectronic products, such as digital cameras, camera phones, bar code readers, and monitors, increase, semiconductor technology for products made therefrom must develop rapidly, as product trends demand the semiconductor chip size to be miniaturized and functionality of the semiconductor chip to be increased and become more complex.
Therefore, more than one semiconductor chip is typically placed in a sealed package, due to performance demands, for operational stability. However, since there is mismatch of the coefficient of thermal expansion (CTE) between a passivation layer and a metal redistribution layer (RDL) in a chip package, the metal RDL easily peels off from conductive pads of the semiconductor chip, thus, reducing the reliability of the chip package.
Accordingly, there is a need to develop a novel package structure capable of mitigating or eliminating the above problems.
A conventional semiconductor structure may include a chip, a landing pad, a dielectric layer, e.g. SiO2, and a redistribution layer (RDL). Generally, when the semiconductor structure is manufactured, a wafer before cut into chips is covered by the dielectric layer to protect an electronic element, e.g., a light sensor, on the wafer. Thereafter, a photolithography process and an etching process may be utilized to remove the wafer and the dielectric layer above the landing pad, such that a via is formed in the wafer and the dielectric layer, and the landing pad is exposed through the via.
Subsequently, an insulating layer, by utilizing a chemical vapor deposition method, may cover a surface of the wafer facing away from the dielectric layer, a surface of the wafer surrounding the via, a surface of the dielectric layer surrounding the via, and a surface of the landing pad facing the via. After the insulating layer is formed, a photolithography process and an etching process may be conducted to remove the insulating layer on the surface of the landing pad, such that the landing pad is exposed through the insulating layer. Finally, the redistribution layer is formed on the insulating layer, such that the redistribution layer may be in electrical contact with the landing pad.
A photomask is required in a photolithography process and an etching process for removing the insulating layer on the landing pad. The cost of the manufacturing process and the process time are therefore increased, which make the improvement of the production capacity even more difficult.